Core catcher



March 26, 1935. c WRIGHT 1,995,336

CORE CATCHER Filed Feb. '7, 1933 34 In venfor 26 Jsse C VW/ghf 20 or bulk.

Patented Mar. 26, 1935 y y 3 1,995,336

UNITED STATES" PATENT OFFICE. A

CORE CATCHER it... 0. Wright, Los Angeles, CallL, asdgnor to Globe on Tools 00.. Los Nietos, CaliL, a corporation of California Application February 7, 1933, Serial No. 655,543

12 Claims. (01. 255-12 This invention has to do with a well core drill, throughout which description reference is had and has particular reference to a core catcher to the accompanyin drawing, in which. for a core drill. It is a general object of the Fig. 1 is a longitudinal detailed sectional view present invention to provide a' simple, practical of a typical core drill embodying the core catcher and dependable core catching means for emprovided by the present invention. Fig. 2 is a 5 bodiment in a core drill for grippi and retaintransverse detailed sectional view taken substaning the core when the drill is withdrawn from tially as indicated by line 22 on Fig. 1 and illusthe w ll, trating the core catcher in an inoperative posi- Another object of the invention is to provide t 3 is a View Similar to 2 S ow a, cor at h r for b i t i core drill the core catcher inthe actuated or core retain- 10 that may he epelated n pp n and holding ing position. Fig. 4 is a central longitudinal engagement with the core by turning or rotating detailed sectional view of the lower end portion the 1 11111 left, d or counter-clockwise of another type of core drill embodying the core ti catcher provided by the present invention.

It is another object of the invention to pro- The core catcher or core catching means pro- 15 vide a core catcher that is extremely simple in vided y the invention may e ppl to mconstr ti a d that may b b di i ibodied in core drills of various types. Further, ous types of or arm with t materially the core catching means may be varied someplicating their structur r adding to th i size what to adapt it for use in various classes of tools. Throughout the following detailed dis- 0 It is another object of the invention to proclosure, I will describe the invention embodiedvide a core catching means that includes a core in two typical forms of core d i being 11!!- gripping member that is forced or operated diderstood that the invention is not to be taken rectly radially into retaining engagement with as limited or restricted to t e speeifie forms the core. The various types of core catchers applications-aboutto be described, but is to be 25 that have been introduced involve either slips ta n as n ud a y f atures or modifications that have longitudinal movement relative to the t a ay a Within p 0f t a msbody or pivoted dogs that have ar uate mo The core drill illustrated in Fig. 1 of the drawment when actuated. As distinguished from the ins in l d s, n l y, a dy/ r outer barrel longitudinal movement of the slips and the piv- 10, an inner barrel 11, a bit head 12 On the lower 30 otal movement of the dogsin the common forms d of t y and the core catch r 3 of core catchers, the core gripping'member of the provided by the p n invention holding core catcher provided by the present invention retaining the core in the inner barrel 11 when moves directly radially into firm positive holding the drill is withdrawn from the well bore.

engagement with the core. The outer barrel or body 10 is an elongate tubu- It is another object of the invention to provide Structure adapted to be t d o the Wer a core catching means for embodiment in a well 0 anoperafing String o drill pipe. The main core drill that includes a ring rotatable in an Principal P01191011 14 0f the body 10 y be eccentric groove in the wall of the core receiving formed f One m lengths of tubing and y opening of the tool, which ring. has an eccentric he provided t its pp nd With 8- Su table Sub 40 opening that is concentric with the opening or. The sub 15 is Provided at its upper end with the drill when th ring is in an inoperative psi a screw threaded pin 16 to facilitate connection tion. and whose walls are forced into gripping of the fzore dnn mm the Stringengagement with the core upon the tool or drill connecting member is provlded on the lower being turned in a reverse or left hand direction. epd of the mam portlon 14.015 the body It is a further object of the invention to proa'sub In he partmular Sfimctur? vide a core catching means of the character trated in the drawmg socket 19 1s provlded m the upper end of the sub 18 and a pin 20 on the mentmned that may be arranged located in lower end of the connecting member 1'7 is threadthe P -d at a Pint immediately adjacent ed into the socket. 'The'sub 1a is provided with h a of h v a. central longitudinal opening 21 for passing the The various obieets andfeatures of the invencore'upwardly into the inner barrel 11 during the t en W h better and fully understood frOm drilling operation. The walls of the sub 18 are the following detailed description of typical comparatively heavy or thick and a tapered pin forms and applications of the invention, -22 projects from the lower end of thesub. 55

The inner barrel 11 is provided to receive or contain the core and is arranged within the outer barrel or body 10. The inner barrel 11 is an elongate tubular structure carried by the sub 18. An enlarged portion 23 on the lower end of the inner barrel 11 is screw-threaded into the opening 21 of the sub 18. The usual valve 24 is provided on the upperend of the inner barrel 11 to permit the escape of fluid from the inner barrel when the core is passing into the barrel and to normally prevent the entrance of circulation fluid into the upper end of the inner barrel. The inner barrel 11 is of less diameter than the opening in the outer barrel or body so that an annular circulation passage 25 is provided between the two barrels.

The bit head 12 is attached to the lower end of the sub 18 and is provided to make an annular out in the earth formation. The bit head 12 includes a tubular body or shoe 26 having a socket 27 in its upper end receiving the screw threaded pin 22 of the sub 18. A plurality of spaced cutting blades 28 project downwardly and outwardly from the lower end or the-shoe 26. The cutting blades 28 project inwardly at the lower end of the shoe opening 29 so as to cut a core that will pass through the opening 29 and the sub opening 21 with suitable clearance. The opening 30 of the inner barrel 11 is of substantially the same diameter as the sub opening 21 and is adapted to readily receive the core.

The core drill illustrated inFig. 1 or the drawing includes means for passing the circulation fluid downwardly to discharge from the lower end of the bit head shoe 26. An enlargement or groove 31 is provided in the interior of the sub 18 at the lower endof the socket 19 and spaced passages 32 extend longitudinally through the walls of the sub. The upper ends of the passages 32 are in communication with the groove 31 which, in turn, is in communication with the lower end of the annular passage 25. An annular groove 33 is provided in the upper end of the shoe 26 to register with the lower ends of the fluid passages 32. Fluid passages-34 extend downwardly through the shoe 26 from the groove 33 to the lower end of the shoe where they discharge the circulation fluid downwardly adjacent the cutting parts 28.

The well core drill described above is merely typical of one class of core drill in which the core catching means provided by the present invention may be embodied, and the invention is not to be construed as limited to the specific details of this particular drill.

The core catcher or core catching means 13 with which the present invention is primarily concerned, is such as to permit the free passage of the core upwardly into the inner barrel 11 during the drilling operation and is operable to tightly grip the core upon the drill being turned in a reverse or left hand direction so that the core may be broken away from the formation and dependably retained in the inner barrel 11 when the drill is withdrawn from the well. The core catching means 13 includes a single member 38 in the form of a ring carried in a groove 39 in the wall of the core receiving opening of the drill.

In accordance with the broader aspects of the invention, the groove 39 for carrying the ring 38 may be located at any desired or practical position and may be provided in any part or member of the drill. In the particular case illustrated in the drawing, the groove 39 is formed in the wall of the sub opening 21. The groove 39 is annular and has fiat upper and lower walls that are substantially normal to the longitudinal axis of thedrill. In the construction illustrated in the drawing, the groove 39 is provided in the wall oi. the opening 21 at the lower end or the inner barrel 11 so that the end of the enlarged portion 23 of the barrel 11 forms a portion of the upper wall of the groove. In accordance with the invention, the groove 39 is eccentric to the core receiving opening 21 or the sub. The outer wall 40 01' the groove 39 is cylindrically curved about a point ofl'set or spaced from the longitudinal axis oi the drill. The core gripping member or ring 38 is turnable or rotatable in the groove 39.

It is a feature of the invention that the core retaining means 13 may include only a single mtegrai ring 38 as illustrated in the drawing. The ring 38 has flat upper and lower ends to cooperate with the opposite ends of the groove 39 and has a cylindrically curved periphery which has rotative engagement with the outer walls 40 of the groove. An opening 41 is provided in the ring 38 to receive or pass the core out by the bit head 12. In accordance with the invention, the opening 41 of the ring 38 is eccentric relative to the cylindrically curved periphery of the ring. The eccentricity of the opening 41 relative to the periphery oi the ring 38 is substantially equal to the eccentricity of the outer walls 40 of the.

groove 39 relative to the sub opening 21. The eccentric opening 41 of the ring 38 is preferably of slightly less diameter than the sub opening 21. When the ring 38 is in its normal or unactuated position, its opening 41'is concentric with the sub opening 21 so as to freely pass the core upwardly into the inner barrel 11.

Core engaging parts or teeth 42 may be provided on the ring 38 for gripping or biting into the core. In the particular case illustrated in the drawing, there is a circumierentially aligned series of core engaging teeth 42 extending substantially-180 around the wall of the opening 41. In accordance with the invention, the series of teeth 42 are provided in the opening 41 where the ring 38 is of the greatest wall thickness so as to project into the core passing opening of the drill when the ring is' actuated. The series 01' teeth 42 may extend along the upper end portion of the ring opening 41 as illustrated in Fig. 1 of the drawing. The teeth 42 may be shaped so as to efiectively cut or bite into the core upon rotation of the ring 38 in a reverse or counterclockwise direction relative to the core. The

teeth 42 illustrated in the drawing have upwardstantially 180 of relative rotary movement between the ring and the body 10. In accordance with the broader principles of the invention, any suitable form of stop means may be embodied in the tool for limiting relative movement between the ring 38 and the body 10. In the form of the invention illustrated in the drawing, a circumrerentially extending slot 45 is provided in the ring 38. The slot 45 is provided in the thin wall portion of the ring 38 and is of substantially 180 extent having its opposite ends adjacent the ends of the series of teeth 42. A' stop 46 through a radial opening in the sub 18 and pro-' jecting from the wall 40 of the groove 39 to extend into the slot 45. The stop pin 46 may have a head threaded into a counter-bore 4'7. It will be apparent how the stop pin 46 is adapted to cooperate with the opposite ends of the slot 45 to limit relative turning between the body 10 andthe core engaging ring 38.

The core catcher 13 may include means on the ring 38 for .yieldingly engaging the core to insure the proper cooperation of the ring 38 with the core so that the ring will be held against rotation when the drill is turned in. a counter-clockwise direction to actuate the ring. Leaf springs 50 are carried by the ring 38 to yieldingly orfrictionally engage the core. In the particular case illustrated in the drawing, the springs 50 project inwardly and rearwardly 'from the teeth 44 relative to the-normal right hand direction of rotation of the drill. The springs 50 in projecting rearwardly from the teeth 42 are flexed outward when the drill is turned in a right hand direction so that they do not interfere with the free passage of the core into the inner barrel 11 but are adapted to grip or slightly bite into the core to hold the ring 38 against turning when the drill is rotated in a left hand direction.

When the core drill is being rotated in the right hand direction indicated by the arrow 51 in Fig. 2 of the-drawing, the core gripping ring 38 is held in its inoperative position where its opening 41 is concentric with the openings 21 and 30 of the drill. The stop pin 46 engages the forward end of the slot 45 causing the ring 38 to rotate with the body when the drill is turned in the right hand direction for drilling. The ring 38, in being in the position illustrated in Fig. 2 of the drawing, does not interfere with the free passage of the core into the core barrel 11. When it is desired to actuate the core catching means the drill is turned in a reverse or left hand direction. Upon turning of the drill in the reverse or left hand direction, the springs 50 engage the core to hold the ring 38 against rotation. The turning of the drill in the reverse or left hand direction,

as indicated by the arrow at 52 in Fig. 3 of the drawing, while the ring 38 is held against rotation, causes the cooperation of the eccentric wall 40 of the groove 39 with the periphery of the ring 38 which forces the ring 38 radially inward so that its teeth 42 are projected into gripping engagement with the core. As the opening 4l.in the ring 38 is eccentric, rotation of the body 10 in a left hand direction relative to the core passing opening of the drill thereby increasing or doubling the radial or inward movement of the core engaging teeth 42 relative to the wall of the opening 21. The cooperation of the walls of the eccentric groove 39 with the ring 38 and the eccentric relation between the ring opening 31 and the core passing opening 21 provides for a substantial inward movement of the toothed portion of the ring 38 so that the ring obtains a firm dependable grip on the core. As only one segment or portion of the core is forced into gripping or holding engagement with the core, the opposite sides of the core are tightly! forced against the walls of the opening 21. The stop 46 limits the reverse or left hand turning of the body 10 relative to the ring 30 so that there is no further movement between the body 10 and ring drill.

38 after the ring has been actuated to its'innermost core'gripping position-illustrated in Fig. 3 of the drawing. v

The ring-38, in being directly carried in the roove 39 transmits the load .or weight of the core directly to the sub 18 of the body. After the ring 38 has obtained its hold on the core the drill.

may be raised to break the core loose from the formation and the ring 38 maintains its grip on the core so that it retains the core in the inner barrel 11 when the drill is withdrawn from the well. It is to be notedthat the toothed portion of the ring 38 is forced directly radially? inward into gripping engagement with the corewhen the ring is actuated to obtain a dependable grip on the core. The ring 38 may be readily released from the core when it-is desired to remove the core from the drill by turning the body 10 in a righthand' direction relative to the core or. by

disconnecting the sub '18 from the connecting member 17. It is to be noted that the core catching .means' 13 is particularly simple asit involves onlya' single moving part. The eccentric face 40 for causing inward movement of 'thei'rin'g 38 is provided by a wall of the groove 30,so that the provision of the core catching means 13 in the drill does not necessitate the adding of material or heavy parts to the drill structure. The eccentric wall 40 is comparatively long tohave long camming or active engagement with the periphery of the ring 38 and its curvature is rela-- drilling so that the core gripping ring 38 is normally maintained in its inoperative position where it does not in any way interfere with the free passage of the core into the inner barrel 11.

Fig. 4- of the drawing illustrates ,the core catching means provided by the present invention applied to or embodied in a single barrel type of core In the single barrel type of core drill and in other forms of tools, it may be practical or desirable to arrange the core gripping ring 38- in a groove in the shoe 61 of the bit head 12*.

The construction and operation of the core gripping ring 38 has been above described and the groove 60 carrying the ring is eccentric relative to the core passing opening 62 of the shoe 61 and has the same purpose and function as the groove 39. In the construction illustrated in Fig.

4 of the drawing, a. connecting member or sub 2 operates in the the manner described above, be-

ing normally in the inoperative position illustrated in Fig. 4, and being actuated into gripping engagement with the core through cooperation with the walls of the eccentric groove 60 when the drill is turned in the reverse or left hand direction. It is to be noted that the core catching and retaining ring 38 embodied in the present invention may be rotatably carried in an eccentric groove provided in any suitable member or part of a core drill.

Having described only typical forms and applications of my invention, I do not wish to limit The sub 63 has a pin myself to the specific forms and details set forth, but wish to reserve to myself any changes or variations that may appear to those skilled in the art or fall within the scope of the following claims.

Having described my invention. I claim:

1. A core drill including, a tubular body, a bit head on the lower end of the body for making an annular cut when the drill is rotated in one direction, and means on the body for gripping the core when the drill is rotated in the other direction, there being a recess in the wall of the body opening, said means including a ring rotatable in the recess and having an eccentric opening concentric with the body opening during operation of the bit head, and means on the ring for engaging the core whereby the opening in the ring is made eccentric relative to the body opening upon turning of the drill in the said other direction.

2. A core drill including, a tubular body, a bit head on the lower end of the body for making an annular cut when the drill is rotated in one direction, and means on the body for gripping the core operable by rotation of the drill in the other direction, there being a recess in the wall of the body opening having a wall eccentric to the body opening, said means including a ring rotatable in the recess and having an eccentric opening that is concentric with the body opening during drilling to pass the core and that is made eccentric to the body opening by rotation of the body in the said other direction.

3. In a core drill, a tubular body, a bit head rigidly connected with the lower end of the body for making an annular cut in the formation when the drill is rotated in one direction, and core catcher means operable upon rotation of the drill in the other direction, said means including a surface on the body eccentrlcally curved relative to the body opening, a member forced radially into the body opening through cooperation with the surface upon turning of the drill in the said other direction, and means on the member normally engaging the core and operable through such engagement to hold the member against rotation when the drill is rotated in the said other direction.

4. In a core drill, a tubular body,-a bit head rigidly connected with the lower end of the body for making an annular cut in the: formation when the drill is rotated in one direction, and means for gripping the core operable upon rotation of the drill in the other direction, the said means including a surface on the interior of the body extending circumferentially relative to the body opening, a member moving radially inward into engagementwith the corethrough rotational cooperation with said surface when the drill is rotated in the said other direction, and means for limiting relative movement between the body and the member.

5. In a core drill, a tubular body, means rigidly connected with the lower end of the body for making an annular cut in the formation when the drill is rotated in one direction, there being a recess in the wall of the body opening, a member carried in the recess and shiftable radially inward into the body opening to grip the core therein through rotational cooperation with the wall of the recess when the drill is turned in the other direction, and means on the member adapted to normally engage the core and operable to hold the member against turning when the drill is turned in the said other direction.

8. In a core drill, a tubular body, means on the lower end of the body for making an annular cut in the formation when the drill is rotated in one direction, there being an annular eccentric recess in the wall of the body opening, a ring rotatable in the recess and having an eccentric opening, means limiting rotation of the ring relative to the body in a position where theeccentric opening is concentric with the body opening when the drill is rotated in the said direction, and means limiting rotation of the ring relative to the body to stop it in a position where its opening is eccentric to the body opening when the drill is rotated in the other direction.

"I. In a core drill, a tubular body, means on the lower end of the body for making an annular cut in the formation when the drill is rotated in one direction, there being an eccentric recess in the wall of the body opening, a ring rotatable in the recess and having an eccentric opening, means limiting rotation between the ring and body to stop the ring in a position where itsopening is concentric with the body opening when the drill is rotated in the said direction and to stop the ring in a position where its opening is eccentric to the body opening when the drill is rotated in the other direction, and parts on the ring to bite into the core when the ring is in the last mentioned position.

8. In a core drill, a tubular body, means on the lower end of the body for making an annular cut in the formation when the drill is rotated in one direction, there being an eccentric recess in the wall of the body opening, a ring rotatable in the recess and having an eccentric opening, means limiting rotation between the ring and body to stop the ring in a position where its opening is concentric with the body opening when the drill is rotated in the said direction and to stop the ring in a position where its opening is eccentric to the body opening when the drill is rotated in the other direction, means on the ring to engage the core in the body when the drill is rotated in the said other direction to hold the ring against rotation, and parts on the ring to bite into the core when the ring is in the last mentioned position.

9. In a core drill, a tubular body, means on the lower end of the body for making anannular cut in the formation when the drill is rotated in one direction, there being an eccentric recess in the wall of the body opening, a ring rotatable in the recess and having an eccentric opening, means limiting rotation between the ring and body to stop the ring in a position where its opening is concentric wlth'the body opening when the drill is rotated in the said direction and to stop the ring in a position where its opening is eccentric to the body opening when the drillis rotated in the other direction, a spring on the ring to engage the core to hold the ring against rotation when the drill is rotated in the said other direction, and teeth on the interior of the ring for gripping the core .when the drill is rotated in the said other direction.

10. A core drill including a body comprising two tubular sections, there being a socket in an end of one of the sections, a pin on the other section threaded into the socket, there being an eccentric recess in the lower end of the socket beyond the pin, means rigidly connected with the lower end of the body for making an annular cut in the formation when the body is rotated in one direction, and a ring in the reces actuated radially inward into holding engagement with the core when the drill is rotated in the other direction.

11. A core drill including, a tubular body, a tubular bit head for making an annular cut in the formation and having a socket in its upper end, a pin fixed on the lower end of the body 5 and threaded into the socket to rigidly connect the bit head with the body, there being an eccentric recess in the bit head at the lower end of the pin, and a ring in the recess operated radially inward into holding engagement with the core 10 when the drill is rotated in a left hand direction.

of the body to cut an annular bore when the body is turned in a forward direction, the body having an internal're'cess, and a member in the recess related to the body for relative turning, the member having an opening concentric with the longitudinal axis of the body during forward turning of the body and made eccentric relative to said axis through the cooperation of the wall of the recess with the member when the body is turned in the reverse direction whereby them member is made to grip the core.

JESSE C. WRIGHT. 

